Add bpf trampoline support for arm64. Most of the logic is the same as x86.
Tested on qemu, result: #18 bpf_tcp_ca:OK #51 dummy_st_ops:OK #55 fentry_fexit:OK #56 fentry_test:OK #57 fexit_bpf2bpf:OK #58 fexit_sleep:OK #59 fexit_stress:OK #60 fexit_test:OK #67 get_func_args_test:OK #68 get_func_ip_test:OK #101 modify_return:OK #233 xdp_bpf2bpf:OK
Also tested bpftrace kfunc/kretfunc and it worked fine.
v3: - Append test results for bpf_tcp_ca, dummy_st_ops, fexit_bpf2bpf, xdp_bpf2bpf - Support to poke bpf progs - Fix return value of arch_prepare_bpf_trampoline() to the total number of bytes instead of number of instructions - Do not check whether CONFIG_DYNAMIC_FTRACE_WITH_REGS is enabled in arch_prepare_bpf_trampoline, since the trampoline may be hooked to a bpf prog - Restrict bpf_arch_text_poke() to poke bpf text only, as kernel functions are poked by ftrace - Rewrite trace_direct_tramp() in inline assembly in trace_selftest.c to avoid messing entry-ftrace.S - isolate arch_ftrace_set_direct_caller() with macro CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS to avoid compile error when this macro is disabled - Some trivial code sytle fixes
v2: https://lore.kernel.org/bpf/20220414162220.1985095-1-xukuohai@huawei.com/ - Add Song's ACK - Change the multi-line comment in is_valid_bpf_tramp_flags() into net style (patch 3) - Fix a deadloop issue in ftrace selftest (patch 2) - Replace pt_regs->x0 with pt_regs->orig_x0 in patch 1 commit message - Replace "bpf trampoline" with "custom trampoline" in patch 1, as ftrace direct call is not only used by bpf trampoline.
v1: https://lore.kernel.org/bpf/20220413054959.1053668-1-xukuohai@huawei.com/
Xu Kuohai (7): arm64: ftrace: Add ftrace direct call support ftrace: Fix deadloop caused by direct call in ftrace selftest bpf: Move is_valid_bpf_tramp_flags() to the public trampoline code bpf, arm64: Impelment bpf_arch_text_poke() for arm64 bpf, arm64: Support to poke bpf prog bpf, arm64: bpf trampoline for arm64 selftests/bpf: Fix trivial typo in fentry_fexit.c
arch/arm64/Kconfig | 2 + arch/arm64/include/asm/ftrace.h | 12 + arch/arm64/kernel/asm-offsets.c | 1 + arch/arm64/kernel/entry-ftrace.S | 18 +- arch/arm64/net/bpf_jit.h | 8 + arch/arm64/net/bpf_jit_comp.c | 446 +++++++++++++++++- arch/x86/net/bpf_jit_comp.c | 20 - include/linux/bpf.h | 5 + kernel/bpf/bpf_struct_ops.c | 4 +- kernel/bpf/trampoline.c | 34 +- kernel/trace/trace_selftest.c | 16 + .../selftests/bpf/prog_tests/fentry_fexit.c | 4 +- 12 files changed, 531 insertions(+), 39 deletions(-)